This invention will be generally discussed in relation to deployment of a stent graft into an iliac artery where it is necessary to extend a side branch from a stent graft into an internal iliac artery but it is to be understood that the invention is not so limited and may relate to any body lumen in which such a deployment is required.
Throughout this specification the term distal with respect to a portion of the aorta, a deployment device or a stent graft is the end of the aorta, deployment device or stent graft further away in the direction of blood flow away from the heart and the term proximal means the portion of the aorta, deployment device or end of the stent graft nearer to the heart. When applied to other vessels similar terms such as caudal and cranial should be understood.
Stent grafts are used for treatment of vasculature in the human or animal body to bypass a repair or defect in the vasculature. For instance, a stent graft may be used to span an aneurism which has occurred in or associated with the iliac artery. In many cases, however, such a damaged or defective portion of the vasculature may include a branch vessel such as an internal iliac artery. Bypassing such a branch vessel without providing blood flow into it can cause problems and hence it has been proposed to provide a side branch on a stent graft which when deployed is positioned over the opening to the internal iliac artery and then another stent graft can be deployed through the side branch into the internal iliac artery to provide a blood flow path to the internal iliac artery.
Generally, when deploying an endovascular stent graft into a body lumen, it is possible to obtain access to such a body lumen from each end of the lumen where necessary, thereby facilitating placement of a device in the lumen. The internal iliac artery which extends from the common iliac artery below the aortic bifurcation is for all intents and purposes a blind vessel because there is no practical way of performing an endovascular minimally invasive procedure into that vessel other than by entry from the common iliac artery. The term blind vessel is used herein to describe such a vessel.
There have been proposals to deploy a branched stent graft into the common iliac artery via a femoral artery from a femoral incision using the Seldinger technique. Such a branched stent graft has a side arm which is placed to extend into or at least adjacent the internal iliac artery and then a leg extension can be placed through the side arm into the internal iliac artery, however, the use of such devices is very dependent upon favourable layout of the arteries and the ability to obtain access over the aortic bifurcation and in many cases, access is extremely difficult.
It has been proposed to use an indwelling auxiliary catheter positioned in the introducer and through the side arm of the stent graft and when it is deployed to use it to assist with directing a deployment device into the internal iliac artery. To do this it is necessary to snare a guide wire extended from the indwelling auxiliary catheter. This is best done through the contra-lateral iliac artery over the aortic bifurcation. Snaring can be a problem because the guide wire being snared can become entangled around the nose cone of the introducer or the guide wire of the introducer.
This invention proposes an alternative method for enabling access to the internal iliac artery and a deployment device to enable such a method to be practiced.
It is the object of this invention therefore to provide an improved deployment device or at least to provide a physician with a useful alternative.